Machines of the aforementioned type with a bale-forming space, which is variable with respect to size of the bale that is to be formed, are known in different designs. Bales of different size but, as far as possible, comparable compression, are to be formed with these machines in order to be able to utilize these machines for different application and requirement. Known machines of this type have one or more bale conveyors(s), the position of which can be changed. These bale conveyors are in the form of bale conveying belts or similar conveying elements, which are guided by deflector rollers, which are secured so that they can pivot. During the bale-forming process, these bale conveyors act together with harvested crop conveyor, which is disposed downstream in the conveying direction from the harvested products receiver, so that the bale conveyor(s) and the harvested crop conveyor act upon the bale that is to be formed during the bale forming process. The German Offenlegungsschrift 37 34 186, for example, discloses a machine of this type, in which two bale conveyors are provided in the form of endless belts, which during the bale forming process work together with a harvested crop conveyor that is disposed in the bottom region of the machine. This harvested crop conveyor likewise has several endless belts, which are disposed next to one another and are driven in a common revolving direction.
As against such machines, conventional, fixed chamber machines are known, in which a cutting device for comminuting the harvested crop that is to be compressed is assigned to the inlet opening of the machine. In particular, such a machine serves for forming a long-fibered harvested crop, such as straw, in the cut state into a bale, which can be broken up more easily for feeding. In the German Offenlegungsschrift 38 16 204, such a machine is described, in which the cutting mechanism has several cutting knives, which are mounted so that they can be swiveled and protrude into a conveying gap or channel of the machine. The cutting tools can be swiveled in such a manner, that in their initial cutting position they do not exert any cutting action on the fiber material. With that, a bale is to be formed, the core region of which consists of uncut fiber material, which beyond that, however, has cut, more easily broken up fiber material. This machine is very expensive to construct, since special conveying and cutting devices with special drives and control elements are required. This has a disadvantageous effect on the production costs.